This invention relates to storage tubes in general and, in particular, to scan converter storage tubes for use in oscilloscopes with a waveform storage capability, analog to digital converters, etc. The invention is more particularly directed to a scan converter storage tube featuring a novel storage target comprising a plurality of collector electrodes, and to a method of its operation.
The scan converter tube is a type of storage tube wherein an input signal to be stored (written) is applied to the deflectors for writing its waveform on the storage target by bombarding the same with the deflected beam of electrons. The stored waveform can be later extracted (read) in the form of an electric signal.
Kato et al. U.S. Pat. No. 4,215,288, dated July 29, 1980, teaches a storage target of improved construction for use in the scan converter tube. This prior art storage target has a collector electrode of a striped or latticed pattern on a storage surface of a storage substrate in the form of a single crystal of insulating material such as sapphire. The electron beam bomardment of the target results in the production of hole-electron couples, which make possible the writing of information at an improved rate. Kato et al. U.S. Pat. No. 4,288,720, dated Sept. 8, 1981, proposes a method of erasing information from that prior art storage target. This patent also discloses, by way of reference, the long familiar method of writing and reading information on and from the standard storage target. For a better understanding of the features and advantages of the instant invention, the conventional method of scan converter storage tube operation may be briefly summarized as comprising the following four modes: